A mobile network is typically divided into different domains as illustrated below in simplified FIG. 1 showing an exemplary communications network. The exemplary communications network includes a radio network 1, a mobile core network 2 and a service network 3 that includes various nodes and applications. Note that the terms radio network and radio access network (RAN) refer to the same network in this description.
The radio network 1 includes ways for a user device to access the communications network, and can include any of a NodeB 4 that attached to a Radio Network Controller (RNC) 5, an eNodeB (evolved Node B) 6, and a WiFi Access Point (AP) 7 that attaches to a WiFi Access Controller 8.
The mobile core network 2 includes mobile core nodes that link the radio network 1 to the service network 3. Examples of such nodes include a Serving Gateway (SGW), Packet Data Network Gateway (PDN Gateway or PGW) and so on.
The service network 3 includes nodes such as servers that provide services to the user device. In this example, a cache server 10, a video server 11, an analytics server 12 and a further server 13 are shown but it will be appreciated that many different types and combinations of servers can be used in the service network 3.
The functionality located in the service network 3 is typically centralized to a few sites and realized without any explicit information exchange and control signalling interaction with the radio network 1. In FIG. 1, only mobile core nodes where user plane traffic is handled are shown, i.e. SGW/PDN GW (or, alternatively, GGSN, Gateway GPRS (General Packet Radio Service) Support Node, in a WCDMA (Wideband Code Division Multiple Access) network) 9. Between the radio network 1 and the SGW/PDN GW (/GGSN) 9, the GTP-U protocol (GPRS Tunnelling Protocol User Plane) is used. Between the SGW/PDN GW (/GGSN) 9 and the service network 3, the Gi interface (i.e. a normal IP network) is used.
There is a current desire in the telecommunications industry to more closely link radio network and service network functionality together in order to optimize service delivery and radio resource usage. For example, data packets sent from the service network 3 could be delayed if the service network 3 it is aware that the radio network 1 is currently congested and experiencing delays. Access specific information (radio awareness) is therefore useful for the service network 3. It is also possible that the radio network 1 can make use of information relating to the service network 3.
There is also a desire to localize and distribute service network functionality further out in the radio network to save transport resources and to optimize delivery times by providing services from locations closer to the user device.
The requirement and uses for access specific information (radio awareness) in the mobile core network 2 and service network 3 are constantly increasing due to new emerging use cases such as optimized cache play-out, context based service tailoring (e.g. location, radio access technology used), and user and network analytics. Furthermore, the radio network can use information about the services in order to optimize the delivery and resource usage in the radio. These use cases and functions therefore require some sort of information exchange and control signalling interaction between the service network 3 and the radio network 1 (e.g. RNC 5, eNB 6, WiFi access controller 8). Functions operating on the user plane also require access to the user plane flow.
The option to extract application specific information from data packet flows by means of packet inspection, and to apply subscriber specific policies, is specified in 3GPP Release 6. It is termed Flow Based Charging (FBC), and later evolved into the 3GPP Policy and Charging Control (PCC) architecture. The initial driver for PCC was to enable differentiated charging, QoS treatment of packet flows and mapping of services to bearers with different QoS. However to optimize the use cases/features discussed above, additional information exchange and explicit control signalling is required between the domains 1, 2, 3.
A problem with existing communications networks is that some data is not available to all functional entities that could potentially use it to optimize service behaviour, radio resource usage and so on.